The price of ivory and increasing demand in China where carved ornaments made from tusks are prized is thought to be linked to the slaughter.

A team led by Dr George Wittemyer, from Colorado State University, found central Africa saw a 63.7 per cent drop in elephant numbers between 2002 and 2012.

The slaughter peaked in 2011 with eight per cent of the continent’s elephants poached – a total of more than 40,000 animals – reducing the species by about three per cent in that year.

‘These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm current ivory consumption is not sustainable,’ the researchers wrote in the journal Proceedings of the National Academy of Sciences.